Chamaepinnularia taihangensis N.N. Cui & Q. Liu, 2023

Cui, Nini, Liu, Qi, Liu, Xudong, Nan, Fangru, Kociolek, John Patrick & Xie, Shulian, 2023, Chamaepinnularia taihangensis sp. nov. (Bacillariophyceae), a new diatom species from Taihang Valley, Shanxi province, China, Phytotaxa 587 (2), pp. 184-192 : 185-186

Chamaepinnularia taihangensis N.N. Cui & Q. Liu sp. nov. Figs 2–20

LM ( Figs 2–11 ):— Large specimens, linear-lanceolate valves with capitate apices and margins with distinct triple curvatures ( Figs 2–8 ). Small specimens, valves elliptic-lanceolate with capitate apices and with or without distinct triple curvature ( Figs 9–11 ). Length 10–14 μm, width 3.0–3.5 μm. Axial area narrow, rhombic, widening toward the middle of valve and nearly reaching the valve margins. Central area rhombic. Striae slightly radiate in the central area and convergent toward the ends, 20–21 in 10 μm. Raphe straight, proximal raphe ends expanded and bent slightly to the same side, the terminal raphe fissures deflected to the same direction.

SEM ( Figs 12–20 ):— Externally, striae composed of elongated chamber-like areolae and covered by vela ( Figs 12–16 ). Raphe straight and filiform. Proximal raphe ends expanded and unilaterally deflected ( Figs 12, 14 ). Terminal raphe curved to hook-shaped and continuing onto the mantle ( Figs 12, 13, 16 ). Axial area narrow, rhombic. Fascias present, forming rhombic central areas ( Fig. 12 ). Internally, areolae openings interrupted by siliceous bridge that divides striae in two parts ( Fig. 17 ), one small, rounded and located on the valve face-mantle junction, whereas the other elongated and located on the valve face. Proximal raphe ends unilaterally hooked ( Fig. 19 ). Terminal raphe ends weakly deflected and terminated as well-developed helictoglossae ( Figs 18, 20 ).

Type:— CHINA. Taihang Valley, Shanxi Province, epiphyton, 35°12’ N, 113°20’ E, 1760 m asl., June 2020 (holotype SXU! slide THS202006086 = Fig. 3 , Freshwater Algal Herbarium of Shanxi University, Taiyuan, China; isotype: COLO slide, J.P. Kociolek Collection).

Etymology:— Named for the region in which it was found.

Ecology and distribution:— C. taihangensis sp. nov. was found in Eight spring gorge, Taihang Valley. Conditions in the type material were as follows: Temperature 17.2 ºC, pH = 8.32, EC = 318.6 µs̽ cm-1, AT = 679.4 mm Hg, dissolved oxygen = 9.57 mg ̽L- 1 and total dissolved solids = 279.50 mg ̽L- 1.

Associated diatom species: — The type population of C. taihangensis sp. nov. was found in samples associated with other species. In THS202006086, two dominant species were Achnanthidium minutissimum (Kützing) Czarnecki (1994: 157) (25.8 %) and Delicata sinensis Krammer & Metzeltin (2003: 121) ( Krammer 2003) (24.0 %). Diatoma moniliformis (Kützing) D.M. Williams (2012: 260) represented 7.5 % of the community with Cymbopleura kuelbsii ( Krammer 2003: 94) (5.8 %), Achnanthidium rivulare Potapova & Ponader (2004: 36) (4.0 %), Achnanthidium pyrenaicum (Hustedt) H.Kobayasi (1997: 148) (3.8 %), Denticula elegans Kützing (1844: 44) (3.0 %), Navicula antonii Lange-Bertalot (2000: 155) (Rumrich, U., Lange-Bertalot, H. & Rumrich, M. 2000) (2.8 %), and Chamaepinnularia taihangensis sp. nov. (2.0 %).

Figures

FIGURES 2–11. Chamaepinnularia taihangensis sp. nov. LM images of valve view showing dimensions range in size. Scale bar = 10 μm.

FIGURES 12–20. Chamaepinnularia taihangensis, SEM. 12–16, external views. 12. Entire valve, showing striae are composed of a elongated chamber-like areolae, and areolae openings covered by vela. 13, 16. View of the apex, with capitate apices, terminal raphe fissures distinct curving, continuing onto the mantle. 14. Center of the valve, showing the proximal raphe expanded and bent slightly to the same side. 15. Showing the siliceous thickening of the vela is thinner and easy to fracture. 17–20, internal views. 17. Entire valve. Showing the areolae openings are interrupted by siliceous bridge that divides striae in two parts.18, 20. View of the apex, distal raphe ends weakly deflected and terminate as helictoglossae. 19. Center of the valve, showing the proximal raphe ends unilaterally hooked. Scale bar = 1 μm.